Splitfires And Their Issues

[sspikey]

I just installed splitfires to relivev my stoc coils which were not doing well anymore and they are running worst than stock....What the heck?

i am gonna play with the gap but my oem ones would slightly miss through the rev range from 4500 on these at 4500 go nuts and get SUPER pissed off.....What the hell gives?

my gap is at .32" i will try to shrink back to .28" but still im skeptical of these anyone else had similar problems?

[Bl4cK32]

how do u know it was the coils at fault to start with?

[Sydneykid]

I just installed splitfires to relivev my stoc coils which were not doing well anymore and they are running worst than stock....What the heck?

i am gonna play with the gap but my oem ones would slightly miss through the rev range from 4500 on these at 4500 go nuts and get SUPER pissed off.....What the hell gives?

my gap is at .32" i will try to shrink back to .28" but still im skeptical of these anyone else had similar problems?

My guess is the original misfiring wasn’t caused by the coils. In fact it has been my experience that it is very rarely actually caused by the standard coils.

The most common cause (at higher than standard boost) is plug gap. The factory setting of 1.1 mm (40 thou) is too wide and the incoming airflow simply blows out the spark Gapping down to 0.8 mm (30 thou) is the most common fix, some need to go to 0.65 mm (25 thou).

The second most common cause is tuning, this is particularly noticeable with the standard ECU. At higher than standard airflows the standard ECU moves into areas of rich and retarded mapping. This is sometimes incorrectly termed “boost cut”, both the word “boost” and the word “cut” are totally inappropriate. Boost is irrelevant, it is not unusual to get R&R mapping at standard boost. It’s the excessive airflow (as sensed by the AFM) that is the real issue. As for “cut”, well the truth is NOTHING is actually cut, the fuel still flows and the ignitor still fires the spark plugs via the coils.

What causes the misfire is the extreme retarded ignition timing more than the rich A/F ratios. At higher rpms (over 5,000 rpm) the retarded ignition timing means that there is simply not enough time for the plug to ignite the mixture before the piston passes TDC. So tuning is basically a juggle between the maximum ignition advance and the minimum knock.

The bottom line for you……..try gapping down to 0.65 mm (25 thou), if that doesn’t work then you have to do some tuning. If you have a standard ECU then the best you can do is try a little bit of ignition advance by rotating the CAS (anticlockwise for advance). If the misfire is light then that generally works. You then rely on the standard ECU knock protection to save your ass.

If you have an aftermarket ECU, then it is simply a matter of gradually advancing the ignition (at the misfire RPM’s) while monitoring the knock levels and/or listening for pre-ignition.

Hope that was of some help

cheers

[GTR_Legend]

I just installed splitfires to relivev my stoc coils which were not doing well anymore and they are running worst than stock....What the heck?

i am gonna play with the gap but my oem ones would slightly miss through the rev range from 4500 on these at 4500 go nuts and get SUPER pissed off.....What the hell gives?

my gap is at .32" i will try to shrink back to .28" but still im skeptical of these anyone else had similar problems?

fixed my miss and work great!

[sspikey]

well heres the deal

i believed it to be the coils because the car was VERY fast and only misfired when the motor became very hot (after 10 mins of hard driving)

but as long as the engine bay was cool nothing was wrong.

i will try regapping the plugs tomorrow and try again itsjust odd the splitfires made everythign worst.

I guess i should mention the car only has downpipes, decat and a full3"muffler

thats it for mods

running NGK 6097 (supra twin turbo spark plugs with some 500-600HP guys around here run

Stock Nismo s tune airfilter element

thats it thats all

[Bl4cK32]

sounds like ignitotor...

[`nigno]

Had a similar problem installed split fires, improved somwhat, changed plugs to NGK IRIWAY7's with a 0.65 gap and my car runs beautifully now, I seriously recommend looking at your plugs as sydneykid has already pointed out costs hardly anything, takes little time and made a big difference for me

[nuffsaid]

I didnt have a miss fire problem, but rather flat spots around 4500-5000 sometimes a little higher

Gapped plugs to 0.8mm and that didnt help much. Why is that? is there another problem? it never had a flat spot when stock.

Should advancing the timing help with this? or a SAFC?

[Sydneykid]

I didnt have a miss fire problem, but rather flat spots around 4500-5000 sometimes a little higher

Gapped plugs to 0.8mm and that didnt help much. Why is that? is there another problem? it never had a flat spot when stock.

1.Should advancing the timing help with this?

2. or a SAFC?

That's what slight R&R mapping feels like, flat response for several hundred rpm. Then it comes back to life. So my suggestions would be;

1. Yes

2. Yes

cheers

[nuffsaid]

Thanks SK, your right, it is flat for a few hundred rpm, then it pulls well.

As a result, will advancing the timing put my GTT at risk of anything? dont want to be blowing things up. I would much rather doing this as it is cheap, and then if this doesnt work, a SAFC might be necessary.

I heard advancing the timing is not good if you dont know what you are doing, but as you said, does the factory ECU have protection modes that will prevent this?

[Sydneykid]

Thanks SK, your right, it is flat for a few hundred rpm, then it pulls well.

As a result, will advancing the timing put my GTT at risk of anything? dont want to be blowing things up. I would much rather doing this as it is cheap, and then if this doesnt work, a SAFC might be necessary.

I heard advancing the timing is not good if you dont know what you are doing, but as you said, does the factory ECU have protection modes that will prevent this?

Do you know what pre-ignition sounds like? If so then get into it, couple of degrees at a time, checking as you go with a timing light. Listen closely, especially during boost build. Normally you can sneak 4 or 5 degrees into them (every engine is different) without a problem.

cheers

[R31Nismoid]

how do u know it was the coils at fault to start with?

exactly what i thought as soon as i read the thread title

And SK has sad what i was pretty much gonna say... other that...

The wrong choice of plugs could also be an issue.. i dont recall anyone using NGK 6097 ... or what type they are.

I would be using the coppers, cant think of the code off the top of my head.

Other issue, as you said bl4ck32 - could be the ignitor if its RB25 Si or RB20 we are talking about

[Sydneykid]

I would be using the coppers, cant think of the code off the top of my head.

BCPR6ES-8

(if not then use -11 and gap them down)

Cheers

[psybic]

That's what slight R&R mapping feels like, flat response for several hundred rpm. Then it comes back to life. So my suggestions would be;

1. Yes

2. Yes

cheers

I bet thats what mine is also... I was thinking coils.... stupid reading forums too much. Everyone always thinks coils on forums.

Good thing I read some sense before I started thinking about splitfires.... Last time I almost bought splitfires it turned out to be low comp on 3 cylinders... people have got to learn to stop assuming coils as soon as something sounds odd.

Is R&R particularily bad on RB25's? Because I have had Stock ECU's in RB26 and SR20 and it wasn't like this.

[Bl4cK32]

Coils and ignitor are top of the list on electrical items in skyliens that cause a missfire when hot.

Just because a car has these symptoms, doesnt mean run out and spend $$ on splitfires or a new ignitor.

Normal people diagnose the problem first before spending...

[Beer Baron]

considering that the problem got worse after you removed (stock) and replaced (splitfires) the coils then perhaps your coil pack loom is the problem. I know of a couple of people who have chased misfire problems and in the end it was the loom. wires get brittle with age and heat cycles. or could be a slightly damaged plug etc etc. look into that possibilty.

[sspikey]

Havent spent a penny yet these are my friend's splitfires hes lettingme use for the lump sum of Zero $

BCp6eS-11 are SR20det spark plugs i will try those thx

[R31Nismoid]

Havent spent a penny yet these are my friend's splitfires hes lettingme use for the lump sum of Zero $

BCp6eS-11 are SR20det spark plugs i will try those thx

bcpR6es-8

You have the wrong number

[sspikey]

So today i closed down the gap to .28" and still a misfire with my old Nismo Spark plugs

going to be swapping the oem set back in AGAIN hoping for the best to see if it returns to the slight missi use to have then swap in a new set of working OEM coilpacks

man i have it down to real quick now at least

can anyone tell me if letting the ignitor just hang without being attached anywhere is ok?

Its a pain putting and removing the the center valve cover.

Oh and yes i did forget to type the R

in case people need to know the stock # is 6662 for the NGK plugs

[sspikey]

considering that the problem got worse after you removed (stock) and replaced (splitfires) the coils then perhaps your coil pack loom is the problem. I know of a couple of people who have chased misfire problems and in the end it was the loom. wires get brittle with age and heat cycles. or could be a slightly damaged plug etc etc. look into that possibilty.

Any tips to checking all this?